Screening to detect medical conditions has become standard practice for many diseases, but insufficient attention has been paid to the potential for harm, according to a study conducted at the University of North Carolina.

“I think guideline groups, just as they are systematic about thinking about benefits, need to be systematic about thinking about harms,” said lead author Harris. “We should not implement a screening program until we know enough to have a clear understanding of both benefits and harms.”

Harris also is professor of medicine in the UNC School of Medicine, adjunct professor of epidemiology in the UNC Gillings Global School of Public Health and member of the UNC Lineberger Comprehensive Cancer Center.

Harris and co-authors outline a framework that can be used by physicians, patients, policy makers and researchers to think systematically about the harms of screening programs. This rationale – a “taxonomy of harms” – makes it easier for decision makers to fully consider all harms to balance against anticipated benefits.

“Harms are any adverse effect that people feel because of screening,” he said. “It is important to take the perspective of the patient, the one who experiences the harm. The whole idea of what we did was to develop a systematic way for people to look at a screening program and decide whether screening makes sense for them, without being blindsided by harms that they didn’t know about and didn’t expect.”

Harris’ team interviewed dozens of policy makers, physicians, researchers and patients to develop four major categories of harm that need to be considered in any screening recommendation:

Physical harm – Potential for a screening procedure to cause physical injury to patient, such as when a colonoscopy perforates the intestine and requires hospitalization;

Psychological harm – Immediate and long-term psychological strain caused by screening (e.g., a patient’s screening test is positive but additional testing is inconclusive, requiring the patient to undergo further surveillance over time without knowing whether he or she has a serious condition);

Financial strain – From initial screening to follow-ups and monitoring, each medical intervention will increase the financial burden on patients, possibly interfering with their financial planning and security; and

Missed opportunities – From the need to miss work to have the initial test to further time to have additional testing – the screening process requires multiple visits and testing. This all becomes a distraction, taking time and attention away from people trying to attend to healthy lifestyle and to taking part in the everyday activities of work and family life.

Because the research on screening traditionally has focused only upon its benefits, little evidence has been collected on the potential for harm. Harris said he hopes his work will spur the collection of such evidence, with an understanding that it must come from the patient perspective.

“Unfortunately, the data is not available in a systematic way. That would be wonderful if we had surveillance systems that we put in place 20 years ago to systematically look at benefits and harms,” Harris said. “Besides being helpful to decision makers today, we hope this taxonomy gives researchers a direction for future research.”

Other study authors include Carmen Lewis, MD, MPH, of the Cecil G. Sheps Center for Health Services Research and the School of Medicine; Colleen Barclay, MPH, of the Sheps Center; and Christine Kistler, MD, MASc, of the Sheps Center and School of Medicine. Harris, Vu, Golin, DeFrank and Brewer are affiliated with the Sheps Center. Harris and Golin have appointments in the School of Medicine; Harris and Brewer are affiliated with UNC Lineberger Comprehensive Cancer Center. Sheridan, whose primary appointment is in the School of Medicine, is also a research fellow at the Sheps Center.